Curtain stretcher



w. w. BLOCK CURTAIN STRETCHER Filed Au 1944 Sept. 1 1950 INVENTOR.

wooden frame member, such as the wooden frame member 16 of Figure 2, having associated as a unit therewith a member or strip 26 which is more stable than soft wood under varying atmospheric conditions and presents a firm or aggressive surface grip to a pin. It has been found, for example, that if the member or insert 26 is made of plastic or certain fibrous laminated materials which will not crack when the pin is driven therethrough, said pin may be permanently secured against loosening.

One embodiment of the invention contemplates a wooden frame, such as the frame member 16, formed with an elongated slot or opening 28, Figure 4, designed to receive the plastic or moisture impervious member 26. The insert 26 may be pressed into the slot 28 or otherwise secured therein. After the insert has been secured as a unit of the frame member the pin 24 may be driven into position, as shown in Figure 2. This type of pin is driven in from the front side of the frame a sufficient distance to penetrate the insert 26. The frame member I6 is cut away at 28 so as to present a narrow section lfia and a heavier section lSb. The portion of the pin 24 projecting beyond the front surface of the narrow section 16a serves to accommodate woven materials such as curtains, fabrics, and the like.

In Figure 3 the frame I6 and the insert 26 are identical with the frame structure shown in Figure 2. A modified pin 30 is shown in Figure 3, said pin being driven through the narrow section lBa of the frame from the rear side of the frame. The pin 30 is provided with a head at its lower extremity which limits the extent to which it may be driven into the frame. Both of the pins 24 and 30 are preferably driven completely through the moisture impervious member or insert 26 and are equipped with knurled or barbed surfaces to facilitate gripping within the frame structure.

From the foregoing it will be apparent that by employing the auxiliary frame insert 26, any variations in the wooden frame part, such as the shrinkage of the wood fibers from the peripheral surface of the pins, or the normal looseness of natural wood fibers, will not cause said pins to loosen. That is to say, the material of the insert 26 is relatively stable compared with the Wood fibers of the frame proper and hence said insert firmly and uniformly impinges the peripheral surface of the pins at all times. Certain types of laminated plastic materials have proven successful, but obviously the invention is not limited to any specific insert material. However, the composition of the material must be such as to maintain a snug or tight fit of the pins within the insert during the life of the curtain stretcher of which the frame forms a part. Stating it another way, the pin accommodating section or insert should have a co-efficient of expansion due to atmospheric moisture which is substantially less than the wooden frame member whereby permanently to secure the pins within the frame member. It is also preferable that the insert be substantially free from shrinkage in a substantially dry atmosphere as compared with the natural wood fibers of the frame.

For purposes of illustration one form of auxiliary frame member, such as the insert 26, has been shown. Obviously, various forms and shapes of pin receiving members may be combined as a unit with the main frame structure without departing from the spirit and scope of the appended claims.

The invention is hereby claimed as follows:

1. In a frame structure for curtain stretchers and the like, an elongated frame member having a longitudinal groove therein, an insert carried by said frame member and substantially filling said groove and formed of a material capable of more firmly, constantly, and uniformly gripping pins to be inserted therein than wood and less affected by temperature and humidity changes, and a plurality of pins each having the outer end thereof disposed exteriorly of said frame member a distance sufficient to accommodate woven materials and each having adjacent portions of the inner end thereof embedded in said frame member and said insert with substantial surface contact therewith whereby the insert will obviate any tendency of the pins to loosen.

2. In a frame structure for curtain and other fabric stretchers, an elongated frame member having a longitudinal groove dis-posed between the front and rear faces of the fabric gripping area thereof, an insert carried by said frame member and substantially filling said groove, and a plurality of pins having one extremity disposed exteriorly of the front face of said frame member a distance suflicient to accommodate the fabric and having the other extremity extending through the adjacent portion of said frame member and into substantial surface contact with said insert, said insert being more resistant to changes in conditions affecting gripping action on the pins than the frame member whereby to restrain said pins from loosening.

3. In a frame structure for curtain stretchers and the like, an elongated frame member having a longitudinal groove therein disposed between the front and rear faces and opening inwardly thereof, an insert carried by said frame member and substantially filling said groove and formed of a material capable of more firmly,

constantly and uniformly gripping impaling pins to be inserted therein as compared to the frame member, and a plurality of pins each having the outer end thereof disposed exteriorly of said frame member a distance suflicient to accommodate woven materials and each having adjacent portions of the inner end thereof extending through said insert in continuous surface contact therewith, and embedded in said frame member on opposite sides of the insert whereby to restrain the pin from loosening.

4. In a frame structure for curtain stretchers and the like, an elongated frame member for transversely accommodating impaling pins, a plurality of impaling pins carried by said frame member with the outer ends of said pins protruding therefrom a distance sufficient to accommodate woven materials, and an insert substantially oblong in cross section carried by said frame member and in which inner portions of the pins are secured, the longer sides of the cross section of said insert contacting said frame member and a shorter side exposed, said insert consisting of a material permitting the pins to be driven therein through an imperforate portion thereof but effective to impinge the embedded pin surfaces more constantly and aggressively than wood whereby to permanently secure the pins thereto.

5. In a frame structure for curtain stretchers and the like, an elongated frame member for transversely accommodating impaling pins, a plurality of impaling pins carried by said frame member with the outer ends of said pins protruding therefrom a distance suflicient to accommodate woven materials, and an insert substantially oblong in cross section carried by said frame member and in which inner portions of the pins are secured, the longer sides of the cross section of said insert contacting said frame member and a shorter side exposed, said pins having the inner end portions thereof roughened and said insert consisting of a material permiting the roughened ends of the pins to be driven therein through an imperforate portion thereof but effective to snugly impinge the embedded roughened ends of the pins for constantly and aggressively gripping the pins more firmly than wood whereby to permanently secure the pins thereto.

6. A curtain stretcher comprising means providing a polygonal frame structure having a plurality of recesses around the periphery thereof, a plurality of pins passing into said recesses and embedded in an adjacent portion of said frame structure, and each of said pins having the free end thereof disposed exteriorly of said frame structure a distance sufficient to accommodate the material to be stretched thereon, and an insert substantially filling each of said recesses and within which said pins are intimately gripped throughout the portions which extend therein, said inserts consisting of a material which permits the pins to be driven thereinto but which is effective to grip the pins more firmly, constantly and uniformly than the material of the frame structure whereby to restrain the pins from loosening.

7. A curtain stretcher comprising means pro viding a polygonal frame structure having a plurality of recesses around the periphery thereof, an insert disposed within each of said recesses and formed of a material capable of gripping impaling pins to be inserted therein more firmly, constantly and uniformly than the material of the frame structure, and a plurality of impaling pins disposed around the periphery of said frame structure with the inner ends thereof extending transversely through said inserts and embedded in portions of said frame structure on opposite sides of said inserts and with the outer ends of said ipins disposed exteriorly of said frame structure a distance suificient to accommodate woven materials.

WALTER W. BLOCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

